Validating a web form
There's no need to copy any images and, especially if your style-sheets are gzip-compressed, there will be next to no impact on load times. The main problem is that if the user doesn't enter a new value, the placeholder text will be submitted along with the form.In a few minutes you could have your whole website updated. I would highly recommend using one the various placeholder polyfill scripts if you want to support the placeholder attribute in older browsers: e.g.Before you ask, and someone always does, these examples will currently work in the following browsers: Safari 5, Chrome 6, Opera 9, Firefox 4 Beta and the i Phone/i Pad.Also each browser has a slightly different default behaviour.As soon as a single character has been entered this changes to a green marker to indicate that the input is 'valid'.Using CSS you can place markers inside or alongside the input box, or simply use background colours and borders as some browsers do by default. On the i Phone/i Pad the different input types are associated with different keyboards, making it easier for people to complete your online forms.
Other HTML5 input types include: -related options do have an effect at least in Opera, with pop-up calendars and other devices appearing to assist with input. But as you see, lots of strange looking URLs are actually valid.
The option of using pure HTML, sometimes with a touch of CSS, to complement Java Script form validation was until recently unthinkable.
Sure there have been all kinds of whacky plug-ins over the years aimed at achieving this, but never a single standard that we could work towards.
In other web browsers they can be used in combination with the .
Obviously neither example is very limiting, but it will prevent people from entering completely wrong values, such as phone number, strings with multiple '@'s or spaces.